Gas engine stall / hesitation

If it were a gas only car - I would say it sounds like the thermostat stuck open - and wouldnt let the engine warm up fully. Perhaps that's the case -- was it windy at all?? the extra air flow through the radiator could have cooled it some more ... but with a thermostat properly working - the engine doesn't send water to the radiator until it's hot enough... anyway.

The only way to know - since toyota doesn't put gauges in the car - would be to hook up a scan tool and drive it - see if the engine is getting up to proper temp... if not - you got a bad thermostat or something...

I don't recommend blocking the radiator like some do here ... if it's working properly - you should never need to.
none the less - it won't hurt to have it looked over ...just in case.
My dad has been a mechanic for over 40 years - mostly at a GM dealership - so my knowledge is mostly based around traditional engines... Toyota does some different things, especially on the hybrids - with electric water pumps, recirculating systems and such, that I'm just not as familiar with yet....

but based on what i know - sounds like a thermostat problem.

 

Did you block lower and upper grill (partially)? What is what is I did.
If you have fan ON and/or defroster the engine will not turn off. Turn everything, especially the fan and the engine should turn off if you go below 70Km/h.

Note that at these temperatures in Edmonton we have been having the engine cools off very fast. I have coolant temp gauge and notice that at major intersections the engine temp coolant can drop down by 10C (if your fan is running).
Driving around city I have noticed that coolant temp hardly goes above 80C and in some cases with coolant temp. at 60C and fan ON the engine will start automatically.

 

I've endured a dozen winters with 3 different generations of Prius here in Minnesota, where it gets just as cold sometimes. I haven't ever used a engine-block heater either, just partial grille-blocking.

Last night's running around was pretty typical, -12C. That usually means a few minutes of the engine running to get some heat, then the ability to drive EV roughly 10 minutes later... with the regular Prius. (With the plug-in, the engine sometimes won't ever start.)

There's never any hesitation. I'd question the fuel currently in the tank. You want to make sure the engine can still adequately breathe too. And of course, make sure the oil is the correct type and not overfilled.

 

Hate to hyjack the thread but wanted to ask you frozen north folk a heater question. Prius v 1500 miles. Temp external 40-55F. Heater set to 70. Fan set to one bar blowing lightly. Yet I never feel any heat coming from any vent. Play with vent choices, no difference. Doesn't matter if first mile or after 50 run. Can't say the cabin is cold at the time but surprised if I turn the temp to 75 I don't feel a short blast of heat. No scanguage. MPG pretty typical 42.5 for mixed early winter driving. Normal?

 

Set the heat a bit higher (~77F) which direction is heat set to blow, feet/windshield or face (middle vent), one bar is a bit too low (try three bars on the fan setting).

 

Went out again (58F out, drove 8 miles, stopped for 10 minutes, drove back 8 miles) and tried 75, tried all settings of directional controls and up to 4 bars for fan. Never felt warm air at any time to my feet though the air being blown was not exactly cold, more tepid. I live in a heat pump house so not expecting something like natural gas heat burst but did expect obvious warmth and wonder at the ability to defrost or deice windows. And when I set it to mixed foot and dash, the amount of air coming from the center vents is anemic even at 3 or 4 fan setting.

I expect heat enough to defrost my feet or clear ice from the windows or for heat to be propelled fast enough to reach the back seat. What I'm asking is 'is this typical' or a problem with my car?

Haven't seen heat this poor since a 30 Ford Model A or maybe early VW bugs.

 

Sounds like you are expecting 75F air to feel hot. It won't. That isn't. You'd need 85F for the sensation of heat. But then you'd be roasting. And sorry, I don't have an effective way to quantify typical.

Question is, why the apprehension to just setting temperature higher? It only affects efficiency when driving extensively in stealth (engine off HV) when the temperature is near or below freezing.

 

Well, you expect fuel saving (that is reason we bought Prius, didn't we) and heat in the winter like your old oil burner; that is not going to happen. Connect any kind of gaget to OBDII that is capable of showing coolant temp. and you will see why your heat doesn't blow hot air.
Every time the engine shuts off and it happens every time your engine is worm and you take your foot off the gas pedal
the engine is not running so it is not generating any heat (it loses heat).
Any standard car after short trip will have a coolant temp about 190F or higher and on 8mile trip you will be lucky if your Prius coolant temp gets 140F
In Canada we have heated seats in a Prius, so it help a lot.

 

Even with the engine running non-stop, efficiency would still be better than a traditional vehicle. Winter isn't a year long event either.

 

Everything you have said above tells me that you are NOT using the 'Auto' climate control feature but are trying to heat your vehicle via manual controls. Try one thing and see what happens. Set your temp for whatever: 70, 72, 75; whatever suits you. Then turn on climate control by pushing in the big center button labeled 'Auto'. If that doesn't solve your problem I'll be surprised.

 

I also commute in Edmonton but I have blocked the lower grill vent in November and it does appear to help in this -24 C weather. Engine shuts off as expected during normal speeds <70 km/h. The insulation I used was 3/4" grey pipe insulation (home depot or Rona both carry it). You need to measure distance between vanes where there is a vertical bar which blocks using a single length. I end up using several small lengths. (all same size to fit between vertical barrier on vanes.

 

I had to make a choice of which car to take on a trip North in several days where it is now snowing. I have owned or maintained over 40 cars over the last 50 years and there is something very different in the heat output and even air flow in my Prius from other current generation cars (wife's current car is a 2011 Avalon) and I'm trying to figure out if it is normal to a Prius v or abnormal in mine or if I'm doing something that would cause it. Avalon, Porsche, CRV all would blow when I asked it to and warm air set at 70 until it got to that temp

As to normal, I have good air flow to my feet (if not terribly warm) but even directing all air to the cabin vents and cranking up the fan I get 5% of the air flow I'd expect from the center vents with slightly better flow from the sides. What am I expecting? I'm expecting the side cabin vents at 4 fan level to be blowing air vigorously against the side window when directed that way.

Went out this AM and measured the air coming from the center console vents and it registered 94F degrees with the side window at 61F and the temp display showing outside at 58F and desired set to 70F. So I guess that heat is not a problem! But even at 4 bars on the fan speed, air didn't feel like it was coming out strong enough that it would be blown into the rear seating area (and there aren't vents back there are there? I don't see any.). I'll try the Auto button though I'd think that even in manual heat mode the fan speed would allow more air into the cabin (recirc not on). Said while dashing upstairs to try it.

Tried Auto and all it seemed to do was direct the air down at my feet and auto-control the fan speed. And you couldn't have Auto on and also the button just to the right of the circular knob that seems to switch the air to the console vents. With that on and the fan at 5 or more bars, the air flow did seem to be somewhat stronger but you were paying for it with added fan noise at those settings.

Maybe it is just getting used to the controls (cockpit error).

Thanks for the suggestions.

 

Tried Auto and all it seemed to do was direct the air down at my feet and auto-control the fan speed. And you couldn't have Auto on and also the button just to the right of the circular knob that seems to switch the air to the console vents. With that on and the fan at 5 or more bars, the air flow did seem to be somewhat stronger but you were paying for it with added fan noise at those settings.

Maybe it is just getting used to the controls (cockpit error).

Thanks for the suggestions.[/quote]


'Auto' mode will set the fan speed and vent modes automatically depending on the current climate conditions in your vehicle. As the vehicle heats up it will reduce fan speed and also change the vents that it uses. It actually works pretty well. That is my opinion anyway, after using it all last winter. At times I did have to over-ride it to defrost my windshield but then after the windshield is clear all you need to do is push the 'Auto' button again to return to auto climate control. And the rear seating area heat vents are under the front seats.